Team analyzes interactions between black hole-dominated galactic nucleus and surrounding star-forming regions
Credit: University of California, Irvine

Astronomers at the University of California, Irvine and other institutions are using the clearest observations ever made to reveal the secrets of the universe.

In a paper being published today in The Astrophysical Journal Letters and currently available on arXiv, the researchers describe their examination of the nearby galaxy They have conducted the most detailed analysis yet of the interactions between the active nucleus and the black hole.

"What we are seeing in this system has been a surprise for us," said the lead author, an assistant research scientist in physics and astronomy at the University of California, Irvine. We can see the winds from the black hole blowing in our direction, but also the'shock heating' of the gas in the central nucleus, which is something we had not expected.

When wind from a black hole in a galaxy's center pushes on dense gas, it creates a shock front thatdeposits energy into the interstellar medium. She said that this effect could affect the formation of stars in two different ways. It can foster the birth of new stars if the gas is compressed into the form of a molecule.

There is a ring of star-forming regions and an active center with a super massive black hole. Dust at the center of these systems makes it difficult to study the dynamics of these systems, which make up about 10% of the entire universe. U and her co-authors were given access to what was behind the veil.

The researchers were able to map several key ionized andmolecular gas emission lines using the telescope's 6.5 meter mirror and advanced suite of tools. A high-velocity outflow of ionized gas that's "blueshifted" means it's coming toward the observer.

Team analyzes interactions between black hole-dominated galactic nucleus and surrounding star-forming regions
Vivian U, UCI assistant research scientist in physics and astronomy, is a member of a James Webb Space Telescope Early Release Science team that’s using access to data from the JWST’s advanced new instruments to learn unexpected things about nuclear dynamics in nearby galaxies. Credit: Steve Zylius / UCI

The ability of the JWST's Mid-Infrared instrument to see not just what's behind the dust but also how things are moving at very small scales has been realized.

She said that the system has a more coherent picture of how the active galactic nucleus is driving out gas. The black hole-driven winds are dumping energy out into the universe.

The fact that it's merging with another galaxy is a significant contributor to the roiling dynamics.

The interaction with another galaxy means that galactic materials are being moved around as a result of tidal forces, and they file towards the center of the galaxy system. She said that the process tends to make the center very dusty. "That's why you need instruments like the ones aboard the JWST that allow us to peer through the dust and facilitate our understanding of the dusty core of the merging of galaxy."

Today's publication is one of the first in a series of papers that analyze data from the early release science program. The data from the JWST offer an in-depth view of how galaxies evolve through the merging mechanism and allow her team to look into the physics of star formation and black hole growth.

Principal investigators include U and Lee Armus at theInfrared Processing & Analysis Center at Caltech. NASA, the European Space Agency and the Canadian Space Agency collaborated to conduct the study.

The Astrophysical Journal Letters published an article titled "Resolving the Circumnuclear Gas Dynamics in NGC 7469 in the Mid-Infrared". There is a book titled "arxiv. 2209.01210."

Journal information: Astrophysical Journal Letters